Jar mill



H. FARKAS Feb. 10, 1959 JAR MILL Filed June 13, 1957 INVENTOR. HOWARD FARKAs ATTORNEY A space and equipment.

to be ground, together with grinding elements such as United States Patent "ice JAR MILL Howard Farkas, New York, N. Y., assignor to The United Stfates Stoneware Co., Tallmadge, Ohio, a corporation Ohio Application June 13, 1951, Serial No. 665,407

- 1 Claim. or. 241-178) This invention relates to jar mills, and, more particularly, to adjustable jar stops to be used in connection therewith to prevent a jar or other container which holds material being treated, from traveling along the shafts of the mill.

Jar mills usually are formed of two long, cylindrical shafts, at least one of which is provided with means for rotating it about its axis. Such a mill may include a third shaft so that two rows of containers (herein called jars) can be rotated simultaneously with economy of The jars each enclose a material pebbles, rocks, steel balls or the like.

' .A jar with material to be ground and a plurality of grinding elements is laid on a mill lengthwise of its axis. The rotating shaft rotates the jar about its axis, and this causes the grinding elements to continually ride up one side of the interior of the jar, and then to fall down on to the other grinding elements and the material to be ground. In this way chemicals, ores, etc. are finely ground.

One difficulty with this simple form of mill is that as the jars are rotated on the shafts they tend to creep along the mill from one end thereof to the other. Thus, two or more of the jars are brought into abutting contact, and if these jars are of different diameters the contact between them interferes with their separate grinding motions.

It is customary to treat several jars simultaneously on 2,873,072 Patented Feb. 10, 1959 away from the shaft to which it is fastened. Then, if the end of the jar which abuts the stop is not perfectly flat, but is provided with ears or the like, these cars will ride up on the sloping surface, and force the jar back away from the stop until the car has cleared the stop. If the wall did not slope backwardly, when an ear contacted the jar stop it would tend to cause the jar to jump from the shafts. Furthermore, by sloping the wall of the stop, unnecessary consumption of energy is avoided by preventing flat frictional contact between the wall of the stop and thesmooth vertical wall of a jar.

Thestops are of annular construction, having an inside diameter the same as the diameter of the shaft of the mill to which they are to be fastened, orif this shaft is rubber covered, the inside diameter of the stops is slightly smaller than the outer diameter of the rubber covering so that the stops grip the shaft firmly. The stop is preferably made in two halves with two screw means for easily separating and joining them. Alternatively, the two halves may be hinged with convenient means for joining them, such as a pivoted hook on one portion and a projection on the other portion to be engaged by the hook, the hook and projection preferably being located in a depressed surface of the jar stop so that in use they are not contacted by a jar.

The invention will be further described in connection with the accompanying drawings, in which Fig. 1 is a plan view of a mill with jar stops and jarsin place;

Fig. 2 is a vertical section on the line 2-2 of Fig. 1;

Fig. 3 is an elevation of a jar stop on a shaft, with an end of a jar contacting it; and

Fig. 4 is a section through a jar stop on the line 4-4 of Fig. 3.

a jar mill, and unless means is provided for preventing I their creeping along the rotating shafts which support them, they may all gradually work to one end of the mill where both ends of the intermediate jars are brought into abutting relation with the adjacent jars and there is even more interference with their free and independent rotation than where only two jars are brought into abutting relation.

According to this invention so-called jar stops are fastened to one or the other or both of the shafts of a mill at intervals so as to limit the distance any one jar may creep along the shafts, and particularly to prevent jars of different diameters from abutting or contacting one another, thus interfering with their different grinding motions. Ordinarily, the entire length of the mill will be divided by such stops into spaces each of which is only long enough to conveniently accommodate a single jar or a series of jars of the same diameter. As it is customary to place jars of different lengths on the same mill, the spacing of these jar stops is usually not uniform. Moreover, the stops of this invention are adjustable-that is, they are not permanently afiixed to the shafts, but their positions with respect to the shafts are adjustable so that jars or series of jars of different lengths can be accommodated on any portion of the mill from time to time. As a jar creeps along the shafts it abuts one of these stops and is thus prevented from contacting the adjacent jar.

The walls 'Of a jar stop preferably slope backwardly,

In the drawings the jar mill is illustrated as being composed of two long, cylindrical, horizontal shafts 1 and 2. The shaft 2 is driven in the direction of the arrow (Fig. 2) and is rubber covered, the covering being indicated by the numeral 3. A plurality of jar stops 5 are fastened to the shaft 1 at different intervals to accommodate jars 6, 7 and 8 of different diameters. Jars 8 being of the same diameter, there is no jar stop between them. As the mill is operated the jars all tend to travel toward one end of the mill, and Fig. 1 shows several jars which have traveled in this direction, abutting ditferent jar stops. The jars are removed and replaced by other jars as required for the grinding of the different materials. Each jar may be used for the treatment of a different material, and the times of treatment may be difierent.

The jar stops'are advantageously made of hard rubber, so they can be tightened with a tight grip on a metal shaft, but other construction materials may be employed. If not composed entirely of a somewhat resilient material, they are preferably covered with such a material so that no damage is done either to them or to the jars when the jars contact them.

As clearly illustrated in Fig. 4, the preferred form of jar stop is made of two identical halves 1t) and 11. One end of each half is provided with a threaded opening 13 to receive a screw 14, the head 15 of which is drawn against the shoulder 16 of an opening 17 in the opposite end of each half. This opening extends through the end so that the head of the screw is accessible at all times.

The walls of the stop may be sheer and perpendicular to the axis of the shaft but in a preferred embodiment of the invention are beveled to produce sloping Walls 20 for contact with the ends of the jars. The tops of the jars illustrated in the drawings are provided with cars 22, and the clamping bars 23 fit under these, with setserews 24 threaded into these bars and tightened Q) I against the tops of the jars to hold them in place. Figure 3 shows an ear of the jar 7 riding up on the beveled surface 20 of a jar stop 5, thereby forcing the top of the jar 7 away from the jar stop a short distance as the jar maintains its horizontal p sition on the shafts. Other types of jars are provided with different types of cars or-projections at an end of a jar which act in the same manner. Instead of being beveled, the sloping walls of a stop may be rounded either concavely or convexly, or otherwise suitably shaped. The outer surface 3 of each stop is preferably cylindrical with the openings 17 located therein.

In utilizing a jar stop, the two halves are placed around one of the shafts such as the shaft 1, the two screws are inserted and tightened, and the jar stop is thus frictionally held to the shaft. It rotates with it. '-Its position is easily adjusted without removing it from the shaft, by simply looseningthe two screws, then shifting the position of the jar stop, and then retightening the screws. The position of a jar stop on the shaft of a mill is thus adjustable so that jars of different sizes are readily accommodate from time to time.

It will be evident to those skilled in the art that various modifications of the jar stop can be utilized and that the stops may be applied to mills of different designs Without avoiding the claim appended hereto. Thus, the stops may be made of different thicknesses and the height of the walls thereof may be varied. The two halves of a jar stop need not be identical. They will be made in different sizes so as to be usable on shafts of different diameters.

What I claim is:

The improvement in jar mills with jar stops releasably fastened at intervals along at least one of the rotatable means thereof, which improvement consists in each jar stop being composed of hard rubber and made in two halves with the ends of the respective halves united to form an annulus of the halves which tightly embraces the rotatable means, one of the joined ends of each half being provided with a threaded opening, and an opening extending through the other end with a shoulder therein adapted to serve as a stop for the head of a screw, and screws joining the two halves with the threads of the respective screws engaged in the threaded openings with their heads drawn against the shoulders of the other openings, the side walls of each half sloping inwardly from its inner diameter to its outer diameter.

References Cited in the file of this patent UNITED STATES PATENTS 178,564 Smith June 13, 1876 395,140 Hill Dec. 25, 1888 527,965 Gilbert Oct. 23, 1894 727,707 Staufier et al. May 12, 1903 977,720 Ellis Dec. 6, 1910 1,024,344 Langevin Apr. 23, 1912 1,179,393 Barry et al. Apr. 18, 1916 1,457,071 Gilbert May 29, 1923 1,940,492 Gale Dec. 19, 1933 2,212,452 Pereny Aug. 20, 1940 2,484,873 Brant Oct. 18, 1949 2,510,858 Black June 6, 1950' 2,525,663 Frye Oct. 10, 1950 2,597,291 Clegg May 20, 1952, 2,653,015 Andrews Sept. 22, 1953- FOREIGN PATENTS 714,766 France Sept. 14, 1931 I 

